`Being too clean can be dangerous`

Michigan: A new study has indicated that young people may suffer more allergies if they are overexposed to anti­bacterial soaps containing triclosan.

Researchers from the University of Michigan School of Public Health also found that excess exposure to higher levels of Bisphenol A among adults might weaken their immune system.

Triclosan is widely used in anti­bacterial soaps, toothpaste, pens, diaper bags and medical devices while Bisphenol A is found in many plastics, including the lining of food cans.

Both are endocrine-disrupting compounds (ECDs) believed to affect health by mimicking or acting on human hormones, said the researchers.

"The triclosan findings in the younger age groups may support the `hygiene hypothesis`, which maintains living in very clean and hygienic environments may impact our exposure to micro-organisms that are beneficial for development of the immune system," said Allison Aiello, associate professor and principal investigator on the study.

Using data from 2003- 006 National Health and Nutrition Examination Survey, the researchers compared urinary Bisphenol A and triclosan levels with diagnosis of allergies and with levels of anti­bodies to the pathogen cytomegalovirus — both considered signs of immune system changes — in a sample of U.S. adults and children over age 6.

"We found that people over age 18 with higher levels of BPA exposure had higher CMV antibody levels, which suggests their cell-mediated immune system may not be functioning properly," said Erin Rees Clayton, a member of the investigative team.

Researchers also found that people aged 18 and under with higher levels of triclosan were more likely to report diagnosis of allergies and hay fever.

There is growing concern among the scientific community and consumer groups that these EDCs are dangerous to humans at lower levels than previously thought.

As an antimicrobial agent found in many household products, triclosan may play a role in changing the micro-organisms to which we are exposed in such a way that our immune system development in childhood is affected, said Aiello.

One surprise finding is that with Bisphenol A exposure, age seems to mat­ter, said Rees Clayton. In peo­ple 18 or older, higher amounts of the compound were associated with higher cytomegalovirus levels, but in peo­ple young­er than 18 the re­verse was true.

"It is possible that a person can be too clean for his or her own good," he added.

He noted that previous animal studies indicated that BPA and triclosan may affect the immune system, but this is the first known study to look at exposure to BPA and triclosan as it relates to human immune function.

One surprise finding is that with BPA exposure, age seems to matter, said Clayton. In people 18 or older, higher amounts of BPA were associated with higher CMV levels, but in people younger than 18 the reverse was true.

The research appears online Nov. 30 in the journal Environmental Health Perspectives.